The Haunted Mask by R. L. Stine (1995, Paperback, Reprint)

this is yet another great book from the goosebump series. in this book, carly beth, who is a "scaredy cat", buys a mask against the store owners warnings. it is the scariest mask she has ever seen. she is completely shock to find that the mask is so much as a perfect fit, that it looks and feels like her own skin. but as halloween night goes on, carly beth starts to change, and it's not good. it's like she's become some sort of wild animal. the only way to change back to normal, is to take the mask off, but it seems to be stuck on her!!!!!!
a great addition for any young reader who likes horror and mystery and r.l. stine.